docs: def distance(self, point):
          """
          Compute the distance (in km) between this point and the given point.
  
          Distance is calculated using pythagoras theorem, where the
          hypotenuse is the distance and the other two sides are the
          horizontal distance (great circle distance) and vertical
          distance (depth difference between the two locations).
  
          :param point:
              Destination point.
          :type point:
              Instance of :class:`Point`
          :returns:
              The distance.
          :rtype:
              float
          """
          return geodetic.distance(self.longitude, self.latitude, self.depth,
                                   point.longitude, point.latitude, point.depth)